Answer:
The correct option is H) these acids change the environment.
Explanation:
Soil can be described as the part of the environment where plants grow. In primary succession, life stars arising in an area which has no soil and only rocks, This is possible because lichens are the organisms which can grow on the rocks. Lichens secrete certain acids which break down these rocks and hence soil begins to form when these rocks break. This makes it possible for other plant species to grow on these lands.
There are all sorts of ways to reconstruct the history of life on Earth. Pinning down when specific events occurred is often tricky, though. For this, biologists depend mainly on dating the rocks in which fossils are found, and by looking at the “molecular clocks” in the DNA of living organisms.
There are problems with each of these methods. The fossil record is like a movie with most of the frames cut out. Because it is so incomplete, it can be difficult to establish exactly when particular evolutionary changes happened.
Modern genetics allows scientists to measure how different species are from each other at a molecular level, and thus to estimate how much time has passed since a single lineage split into different species. Confounding factors rack up for species that are very distantly related, making the earlier dates more uncertain.
These difficulties mean that the dates in the timeline should be taken as approximate. As a general rule, they become more uncertain the further back along the geological timescale we look. Dates that are very uncertain are marked with a question mark.
Answer:
the answer is A. E. coli B
Explanation:
The multiplicity of infection (MOI) refers to the ratio between the numbers of viruses used to infect <em>E. coli</em> cells and the numbers of these <em>E. coli </em>cells. Benzer carried out several experiments in order to define the gene in regard to function. Benzer observed that <em>E. coli </em>strains with point mutations could be classified into two (2) complementary classes regarding coinfection using the restrictive strain as the host. With regard to his experiments, Benzer observed that rII1 and rII2 mutants (rapid lysis mutants) are complementary when they produce progeny after coinfect E. coli K (where neither mutant can lyse the host by itself). The rII group of mutants studied by Benzer does not produce plaques on <em>E. coli</em> K strains that carry phage λ (lysogenic for λ), but they produce plaques on <em>E. coli</em> B strains. This study showed that rIIA and rIIB are different genes and/or cistrons in the rII region.
